Update dependency gscan to v6

Author: renovate[bot]

package.json

@@ -50,7 +50,7 @@
         "autoprefixer": "10.4.24",
         "beeper": "2.1.0",
         "cssnano": "7.1.2",
-        "gscan": "5.2.4",
+        "gscan": "6.0.0",
         "gulp": "5.0.1",
         "gulp-concat": "2.6.1",
         "gulp-livereload": "4.0.2",